6. Conclusion

Thermal networks have developed to varying degrees in different countries. These differences in development are due to a number of factors, the most important of which are the structure of primary energy resources and the energy policies of the various countries. Technical solutions have been continually modified to improve energy performance and reduce costs. It is expected that as the proportion of renewable energies in heat production increases, thermal networks will be developed on a much larger scale. The consumption densities for which thermal networks are recommended have fallen and will continue to fall.